This invention relates generally to a key storage device for holding one or two keys, the device itself being of a size and shape suitable for storage within a wallet, billfold, or pocketbook. The maintenance of a backup or a spare key for emergency purposes is desirable because keys are commonly lost or misplaced. One of the problems with maintenance of backup or spare keys is that they themselves are susceptible to being lost or misplaced. Storage of backup or spare keys in a wallet or billfold is desirable because such items are less susceptible to being lost or misplaced. However, insertion of an unprotected key into a wallet or billfold is undesirable because the rough edges of the key may cause gouging or tearing of the billfold material. Thus, it is desirable to provide a key receptacle fitted for insertion into a wallet or billfold for storage of spare or backup keys.